Pressure- and Temperature-Dependent Density Change of Juices During Concentration

Density of seven fruit juices (melon, plum, peach, black currants, cherry-plum, pear, and tangerine) have been measured at temperatures from 283 to 403 K and at pressures from 0.1 to 10 MPa for the concentrations of soluble solids from 10.7 to 70°Brix. Measurements were made with a hydrostatic weighing technique. The uncertainty of the density measurements was estimated to be less than 0.075%. The effect of temperature, pressure, and concentration on the fruit juice density was studied. The applicability and predictive capability of the various models for the density of fruit juices were studied. Various polynomials, power, exponential, logarithmic, and their combinations correlation models were used to represent the combined effect of temperature and concentration on the density. Models which represent the density of juice relative to pure water density were considered.